Inkjet printer devices generally incorporate one or more inkjet cartridges, often called “pens”, which shoot drops of ink onto a page or sheet of print media. For instance, two earlier thermal ink ejection mechanisms are shown in U.S. Pat. Nos. 5,278,584 and 4,683,481, both assigned to the present assignee, Hewlett-Packard Company. The pens are usually mounted on a carriage, which is arranged to scan across a scan axis relative to a sheet of print media as the pens print a series of individual drops of ink on the print media forming a band or “swath” of an image, such as a picture, chart or text.
Inkjet printers are generally arranged to print in a variety of print modes that offer differing trade-offs between print quality and throughput. In high throughput modes, the print media may be advanced relative to the carriage by a distance equal to the height of a swath once a given swath is printed. In this manner, a further swath may then be printed adjacent to the earlier swath. By a repetition of this process, a complete printed page may be produced in an incremental manner.
Over recent years, the importance placed on the throughput of ink jet printers has risen dramatically. Throughput is generally measured as the number of pages of a given size, or the area of print media that a printer may ink in a given time. Consequently, manufacturers of inkjet devices have embarked on a process of continually improving their inkjet printers to give improved throughput in order to secure a competitive edge in the marketplace.
Throughput is directly related to the speed at which each swath may be printed. Therefore, in order to enable higher throughputs, inkjet devices have been developed to print at higher carriage speeds, thus allowing more swaths to be printed in a given time. However, as the carriage speed increases above a certain point, the print quality tends to deteriorate. In many cases, it is therefore preferable to print images of higher quality at a lower throughput than lower quality images at a higher throughput. Consequently, inkjet printers are being continually redeveloped to use printheads having increasingly large swath heights. By using printheads with larger swath heights, fewer swaths are needed to print a given print job. Thus, throughput may be increased.
However, even with the advent of printheads with a swath height of approximately an inch, and the prospect of printheads with significantly greater swath heights being available in the future, the demand for yet further increases in throughput remains. This is particularly true as inkjet technology is now being used or considered for use in fields traditionally dominated by other technologies.
It would therefore be desirable to provide an improved inkjet device and a method of operating an inkjet printer that addresses the problems of the prior art.